Noble effort there, Mr. Clark. Much appreciated.

Here is the one which (quietly) disturbs my belief system and was the reason for the definition request: crosspicking. I have understood that the use of adjacent strings and an DUDUDUDU was conventional "flatpicking" al la Django, Don Reno and (most of) Doc Watson's work, and that it became the subset "crosspicking" when you skipped over adjacent strings to sound those two or more strings away.

The DDUDDUDU pattern was just one Clerence White liked and other patterns were used and constantly varied in most songs. That pattern and jumping over adjacent strings is definitely "crosspicking" by anybody's definition, but not necessarily the only version. This is just an effort to define terms and understand things better, and is in no way an attempt to disagree.